Fouling behavior of nano/microplastics and COD, TOC, and TN removal in MBR: A comparative study

The global upsurge in plastic demand has overwhelmed waste management systems, with nano/microplastic (N/MP) pollution emerging as a critical environmental challenge. With wastewater treatment plants (WWTPs) identified as a key source of MPs release to the aquatic environment, reflecting the design limitations in addressing MPs. Herein, this comparative study proposes a novel application of a complete mixed anoxic-oxidation membrane bioreactor (MBR) integrated with three varying polyvinylidene fluoride (PVDF) hollow fiber (HF) membranes for N/MP removal. The fouling behavior of MPs within the MBR was investigated to provide insight on the NPs rejection capabilities of the MBR. The results demonstrate high organics rejection efficiency (99.43% ± 0.13%), complete removal of NPs, and a direct correlation between membrane hydrophilicity and fouling resistance. Notably, hydrophilic and smooth membranes promoted the interaction of microbial aggregation and agglomerations of NPs, enhancing their capture. This study highlights the pivotal mechanism and role of membrane selection in optimizing MBR as an adaptable and effective solution for mitigating N/MPs pollution in wastewater. PRACTITIONER POINTS: Microplastics pollution in membrane bioreactor. Fouling mechanism of microplastics in membrane bioreactor. Fouling behavior of microplastics in membrane bioreactor. Interaction of microplastics and membrane bioreactor. Fouling resistance of microplastics in membrane bioreactor.